Project Summary

This research addresses a gap in knowledge at the interface between traffic microscopic simulation models and project-scale MOVES modeling of vehicle emissions. To date, microsimulation models have not been calibrated and validated at the link-scale; that is, it is unknown whether the fine-grained (>1 Hz temporal resolution) vehicle dynamics (vehicle speed, acceleration) output of a microsimulation model is an accurate representation of real-world, on-road vehicle behavior at this time scale, and further, whether the microsimulation model second-by-second vehicle behavior can appropriately be used directly as inputs to the EPA’s new mobile source emissions model, MOVES, to give accurate tailpipe emissions. Given that March 2012 will mark the start of regulatory requirements for conducting Project-Level analysis for CO and PM in NAAQS non-attainment and maintenance areas using MOVES2010, the current lack of best practices for calibrating traffic activity to MOVES emissions signifies a need for the proposed research.

Using the real-world vehicle TOTEMS emissions database collected by the University of Vermont and
two microsimulation models (TransModeler and VISSIM) a framework will be developed to integrate, calibrateand validate these models with MOVES. This research will (1) be one of the first studies to compare MOVES output directly to real-world, on-board tailpipe emissions data; (2) quantify how well microsimulation vehicle activity inputs affect MOVES emissions output; and (3) evaluate microsimulation model parameters and methods that have the greatest influence on MOVES emissions. This research will enable future work to better quantify these identified parameters (road curvature, grade and driver behavior).